This strategy has won over time, with Buffett scoring major gains from his biggest holding, Apple, as well as longtime favorites such as Coca-Cola and American Express. Today, Berkshire Hathaway's portfolio is worth more than $279 billion. That's compared to a value of about $107 billion a decade ago.

But neither Apple nor U.S. Treasuries ranks as the top holding in Buffett's personal portfolio. It's no secret where the legendary investor has most of his money invested. Buffett's money is primarily in Berkshire Hathway.

Warren Buffett has never shied away from offering investing tips and philosophies to the masses. It's been part of his legacy for the last half-century or so. Among all the gems he's passed along, one piece of advice always remains the same: Most people only need to invest in the S&P 500 over the long term to build wealth.

Warren Buffett is one of the world's richest people, with a reported net worth of around $141 billion, and he earned every dime with smart investments and by living frugally. Born during the